Improved Cigarette Filters Comprising Compound Fibers

ABSTRACT

An improved cigarette filter material/method is provided, especially a compound fiber filter. Cylindrical, with paper tube, filled with tow of interconnected compound fibers in parallel with the cylindrical axis. Said compound fiber comprises a fiber core with a surface layer made from adsorptive materials on. The adsorptive material and the improved filter can effectively adsorb harmful substances from tobacco smoke, and not affect the cigarette taste or flavor.

CROSS REFERENCE TO RELATED PATENT APPLICATION

This application claims the priority benefit of the Chinese patentapplication No. 200520011670.X filed on Apr. 7, 2005.

FIELD OF THE INVENTION

The invention relates to cigarette filters, especially compound fibercigarette filter rods.

BACKGROUND OF THE INVENTION

In recent years, due to the influence of World Health Organization andvarious anti-smoking movements, some developed countries have startedlimiting the component of tar, nicotine, and carbon monoxide, etc in thecigarettes. The raised health awareness of consumers also pushesmanufacturers to produce cigarette products with lower levels of harmfulsubstances, to reduce the damage to consumers.

As shown in FIG. 1, cigarette filter rods are usually cylindrical rodsof size 7.7×120 mm (D×L) or the scale thereabout. The filter rods arecut into segments of certain lengths and attached to the cigarette as afilter mechanism while smoking cigarettes. On the outside of the rod ispaper. The paper tube is filled with tow of interconnected compoundfibers in parallel with the cylindrical axis. The fibers are usuallyCellulose acetate fiber, Polypropylene fiber, etc. Polypropylene fiberhas an alkyl surface, and is chemically inactive. Cellulose acetatefiber has a mostly acetate surface, and is average in the level ofchemical activity. These chemical characteristics limit theeffectiveness of filter rods for removing harmful substances.

SUMMARY OF THE INVENTION

The present invention relates to overcoming the inadequacies of currentfilter technologies, providing a compound fiber filter rod thateffectively adsorbs harmful substances in cigarette smoking, whilepreserves or improves the taste of the cigarette. The presentinvention's technical solution: a compound fiber filter rod. It iscylindrical, with paper tube as the outer shell, filled with tow ofinterconnected compound fibers in parallel with the cylindrical axis.Said compound fiber is comprised of filter fiber core and adsorptivematerials, which attach on the surface. The present invention has thefollowing characteristics:

1. The filter rod's physical attributes, such as circumference,roundness hardness, and draw resistance comply with filter rodrequirements of a cigarette.

2. The filter rod has strong adsorptive filter materials with largersurface area, and it is effective in filtering tar, carbon monoxide,free radicals, and other harmful substances in cigarette smoke.

3. The filter rod does not negatively affect the taste of the cigarette.

4. The filter rod is non-toxic, tasteless, and high safety. The filterrod is safely produced in a clean environment with no unpleasant smells.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the cigarette filter rod.

FIG. 2 is a cross section view of the cigarette filter rod.

FIG. 3 is an enlarged view of part A in FIG. 2.

FIG. 4 is a schematic representation showing the structure of thecompound fiber.

FIG. 5 is a schematic representation showing the adsorptive material.

DETAILED DESCRIPTION OF THE INVENTION

As shown in the FIG. 2 the present invention has an outer shell papertube (1). The paper tube (1) is filled with tow of compound fibers (2)in parallel with the cylindrical axis. The fibers are interconnected (3)to form a filter rod with high permeability.

The compound fibers within the paper tube have the total count of 9000or greater. Optimally, 12000 or greater.

As shown in FIG. 4, said compound fiber (2) comprises a core (21) and asurface layer (22). The core (21) is generally cigarette filter fibers,such as polypropylene fiber, cellulose acetate fiber, etc. The surfacelayer (22) comprises adsorptive material(s). The surface is rich in ionexchange groups and bases.

The core (21) generally has a diameter of 20 μm or thinner (≦20 μm) andthe surface layer 0.5 μm or greater (≧0.5 μm).

As shown in FIG. 5, the adsorptive material has an affinity to the core.As shown, one side is hydrophilic (24), and the other side lipophilic(25). The lipophilic material attaches the adsorptive material to thecore, while also completes the inter-fiber “welding”. In other words,this adsorptive material builds the construction of the compound filterrod. To increase the compound fiber filter rod's effectiveness inreducing tar and other harmful substances, other materials can also beadded to the fibers, such as porous absorbers, Chinese medicinal herbextracts, biochemical substances, and other strong adsorptive materialagainst harmful substances in tobacco smoke.

Although the description above contains many specificities, these shouldnot be construed as limiting the scope of the invention but as merelyproviding illustrations of some of the presently preferred embodimentsof this invention. Thus the scope of the invention should be determinedby the appended claims and their legal equivalents, rather than by theexamples given.

1. A cigarette filter comprising a paper tube; compound fibers which isfilled in said tube in parallel with the axis of said tube; saidcompound fibers being interconnected to form the filter having highpermeability.
 2. The cigarette filter of claim 1, wherein said compoundfiber Comprises a fiber core and a surface layer made from adsorptivematerials.
 3. The cigarette filter of claim 2, wherein the diameter ofsaid fiber Core is 20 μm or thinner (≦20 μm), and the thickness of saidsurface layer is 0.5 μm or greater (≧0.5 μm).
 4. The cigarette filter ofclaim 1, wherein the total count of said fibers is greater than
 9000. 5.The cigarette filter of claim 2, wherein the total count of fibers isgreater than
 9000. 6. The cigarette filter of claim 1, wherein the totalcount of fibers is greater than
 12000. 7. The cigarette filter rod ofclaim 2, wherein the total count of fibers within the paper tube isgreater than
 12000. 8. The cigarette filter of claim 2, wherein saidcore is polypropylene fiber or cellulose acetate fiber.
 9. The cigarettefilter of claim 2, wherein said adsorptive material has an affinity tosaid core, its one side is hydrophilic, and the other side is lipophilicwhich attaches said adsorptive material to said core.
 10. The cigarettefilter of claim 9, wherein said adsorptive materials are rich in ionexchange groups and bases.
 11. The cigarette filter of claim 1, whereinsaid compound fiber is covered with porous adsorptive material, orherbal extracts, or biochemical substances, or other strong adsorptivematerial against harmful substances in tobacco smoke.
 12. The cigarettefilter of claim 2, wherein the fiber is covered with porous adsorptivematerial, or herbal extracts, or biochemical substances, or other strongadsorptive material against harmful substances in tobacco smoke.